Accepting request 792408 from home:michael-chang:gcc10

- Fix GCC 10 build fail (bsc#1158189)
  * 0001-mdraid1x_linux-Fix-gcc10-error-Werror-array-bounds.patch
  * 0002-zfs-Fix-gcc10-error-Werror-zero-length-bounds.patch

OBS-URL: https://build.opensuse.org/request/show/792408
OBS-URL: https://build.opensuse.org/package/show/Base:System/grub2?expand=0&rev=353

0001-mdraid1x_linux-Fix-gcc10-error-Werror-array-bounds.patch

@@ -0,0 +1,52 @@
+From fe8a83722bf1af7ea3949e6d96e7906407f78d5c Mon Sep 17 00:00:00 2001
+From: Michael Chang <mchang@suse.com>
+Date: Wed, 25 Mar 2020 13:52:51 +0800
+Subject: [PATCH 1/2] mdraid1x_linux: Fix gcc10 error -Werror=array-bounds
+
+We bumped into the build error while testing gcc-10 pre-release.
+
+../../grub-core/disk/mdraid1x_linux.c: In function 'grub_mdraid_detect':
+../../grub-core/disk/mdraid1x_linux.c:181:15: error: array subscript <unknown> is outside array bounds of 'grub_uint16_t[0]' {aka 'short unsigned int[0]'} [-Werror=array-bounds]
+  181 |      (char *) &sb.dev_roles[grub_le_to_cpu32 (sb.dev_number)]
+      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+../../grub-core/disk/mdraid1x_linux.c:98:17: note: while referencing 'dev_roles'
+   98 |   grub_uint16_t dev_roles[0]; /* Role in array, or 0xffff for a spare, or 0xfffe for faulty.  */
+      |                 ^~~~~~~~~
+../../grub-core/disk/mdraid1x_linux.c:127:33: note: defined here 'sb'
+  127 |       struct grub_raid_super_1x sb;
+      |                                 ^~
+cc1: all warnings being treated as errors
+
+Apparently gcc issues the warning when trying to access sb.dev_roles
+array's member, since it is a zero length array as the last element of
+struct grub_raid_super_1x that is allocated sparsely without extra
+chunks for the trailing bits, so the warning looks legitimate in this
+regard.
+
+As the whole thing here is doing offset computation, it is undue to use
+syntax that would imply array member access then take address from it
+later. Instead we could accomplish the same thing through basic array
+pointer arithmetic to pacify the warning.
+
+Signed-off-by: Michael Chang <mchang@suse.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/disk/mdraid1x_linux.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/grub-core/disk/mdraid1x_linux.c b/grub-core/disk/mdraid1x_linux.c
+index 7cc80d3df..c980feba4 100644
+--- a/grub-core/disk/mdraid1x_linux.c
++++ b/grub-core/disk/mdraid1x_linux.c
+@@ -178,7 +178,7 @@ grub_mdraid_detect (grub_disk_t disk,
+ 	return NULL;
+ 
+       if (grub_disk_read (disk, sector, 
+-			  (char *) &sb.dev_roles[grub_le_to_cpu32 (sb.dev_number)]
++			  (char *) (sb.dev_roles + grub_le_to_cpu32 (sb.dev_number))
+ 			  - (char *) &sb,
+ 			  sizeof (role), &role))
+ 	return NULL;
+-- 
+2.16.4
+

0002-zfs-Fix-gcc10-error-Werror-zero-length-bounds.patch

@@ -0,0 +1,87 @@
+From 30379c2280c5b4514abafc2492e081209a330cb0 Mon Sep 17 00:00:00 2001
+From: Michael Chang <mchang@suse.com>
+Date: Wed, 25 Mar 2020 14:28:15 +0800
+Subject: [PATCH 2/2] zfs: Fix gcc10 error -Werror=zero-length-bounds
+
+We bumped into the build error while testing gcc-10 pre-release.
+
+In file included from ../../include/grub/file.h:22,
+		from ../../grub-core/fs/zfs/zfs.c:34:
+../../grub-core/fs/zfs/zfs.c: In function 'zap_leaf_lookup':
+../../grub-core/fs/zfs/zfs.c:2263:44: error: array subscript '<unknown>' is outside the bounds of an interior zero-length array 'grub_uint16_t[0]' {aka 'short unsigned int[0]'} [-Werror=zero-length-bounds]
+2263 |   for (chunk = grub_zfs_to_cpu16 (l->l_hash[LEAF_HASH (blksft, h, l)], endian);
+../../include/grub/types.h:241:48: note: in definition of macro 'grub_le_to_cpu16'
+ 241 | # define grub_le_to_cpu16(x) ((grub_uint16_t) (x))
+     |                                                ^
+../../grub-core/fs/zfs/zfs.c:2263:16: note: in expansion of macro 'grub_zfs_to_cpu16'
+2263 |   for (chunk = grub_zfs_to_cpu16 (l->l_hash[LEAF_HASH (blksft, h, l)], endian);
+     |                ^~~~~~~~~~~~~~~~~
+In file included from ../../grub-core/fs/zfs/zfs.c:48:
+../../include/grub/zfs/zap_leaf.h:72:16: note: while referencing 'l_hash'
+  72 |  grub_uint16_t l_hash[0];
+     |                ^~~~~~
+
+Here I'd like to quote from the gcc document [1] which seems best to
+explain what is going on here.
+
+"Although the size of a zero-length array is zero, an array member of
+this kind may increase the size of the enclosing type as a result of
+tail padding. The offset of a zero-length array member from the
+beginning of the enclosing structure is the same as the offset of an
+array with one or more elements of the same type. The alignment of a
+zero-length array is the same as the alignment of its elements.
+
+Declaring zero-length arrays in other contexts, including as interior
+members of structure objects or as non-member objects, is discouraged.
+Accessing elements of zero-length arrays declared in such contexts is
+undefined and may be diagnosed."
+
+The l_hash[0] is apparnetly an interior member to the enclosed structure
+while l_entries[0] is the trailing member. And the offending code tries
+to access members in l_hash[0] array that triggers the diagnose.
+
+Given that the l_entries[0] is used to get proper alignment to access
+leaf chunks, we can accomplish the same thing through the ALIGN_UP macro
+thus eliminating l_entries[0] from the structure. In this way we can
+pacify the warning as l_hash[0] now becomes the last member to the
+enclosed structure.
+
+[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
+
+Signed-off-by: Michael Chang <mchang@suse.com>
+---
+ grub-core/fs/zfs/zfs.c      | 5 ++++-
+ include/grub/zfs/zap_leaf.h | 1 -
+ 2 files changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/grub-core/fs/zfs/zfs.c b/grub-core/fs/zfs/zfs.c
+index 2f72e42bf..b5e10fd0b 100644
+--- a/grub-core/fs/zfs/zfs.c
++++ b/grub-core/fs/zfs/zfs.c
+@@ -141,7 +141,10 @@ ZAP_LEAF_NUMCHUNKS (int bs)
+ static inline zap_leaf_chunk_t *
+ ZAP_LEAF_CHUNK (zap_leaf_phys_t *l, int bs, int idx)
+ {
+-  return &((zap_leaf_chunk_t *) (l->l_entries 
++  grub_properly_aligned_t *l_entries;
++
++  l_entries = (grub_properly_aligned_t *) ALIGN_UP((grub_addr_t)l->l_hash, sizeof (grub_properly_aligned_t));
++  return &((zap_leaf_chunk_t *) (l_entries
+ 				 + (ZAP_LEAF_HASH_NUMENTRIES(bs) * 2)
+ 				 / sizeof (grub_properly_aligned_t)))[idx];
+ }
+diff --git a/include/grub/zfs/zap_leaf.h b/include/grub/zfs/zap_leaf.h
+index 95c67dcba..11447c166 100644
+--- a/include/grub/zfs/zap_leaf.h
++++ b/include/grub/zfs/zap_leaf.h
+@@ -70,7 +70,6 @@ typedef struct zap_leaf_phys {
+ 	 */
+ 
+ 	grub_uint16_t l_hash[0];
+-        grub_properly_aligned_t l_entries[0];
+ } zap_leaf_phys_t;
+ 
+ typedef union zap_leaf_chunk {
+-- 
+2.16.4
+

grub2.changes

@@ -1,3 +1,10 @@
+-------------------------------------------------------------------
+Tue Mar 24 08:17:33 UTC 2020 - Michael Chang <mchang@suse.com>
+
+- Fix GCC 10 build fail (bsc#1158189)
+  * 0001-mdraid1x_linux-Fix-gcc10-error-Werror-array-bounds.patch
+  * 0002-zfs-Fix-gcc10-error-Werror-zero-length-bounds.patch
+
 -------------------------------------------------------------------
 Fri Mar 20 10:36:54 UTC 2020 - Michael Chang <mchang@suse.com>
 

grub2.spec

@@ -291,6 +291,9 @@ Patch511:       grub2-gfxmenu-support-scrolling-menu-entry-s-text.patch
 Patch601:       risc-v-fix-computation-of-pc-relative-relocation-offset.patch
 Patch602:       risc-v-add-clzdi2-symbol.patch
 Patch603:       grub-install-define-default-platform-for-risc-v.patch
+# Fix gcc-10 build fail
+Patch610:       0001-mdraid1x_linux-Fix-gcc10-error-Werror-array-bounds.patch
+Patch611:       0002-zfs-Fix-gcc10-error-Werror-zero-length-bounds.patch
 # bsc#1166409 - Grub netbooting does not search for grub.cfg files with mac
 # address or ip address in filename
 Patch700:       0001-normal-Move-common-datetime-functions-out-of-the-nor.patch
@@ -594,6 +597,8 @@ swap partition while in resuming
 %patch601 -p1
 %patch602 -p1
 %patch603 -p1
+%patch610 -p1
+%patch611 -p1
 %patch700 -p1
 %patch701 -p1
 %patch702 -p1